top of page

TROUBLESHOOTING

Troubleshooting image 1

CRATERING

(REJECTION)

Troubleshooting image 5

OUTGASSING FROM SLAB

Troubleshooting image 2

LOSS OF WET EDGE / OVERLAP MARKS

Troubleshooting image 6

AIR BUBBLES

IN COATING

Troubleshooting image 3

DE-LAMINATION /

PEELING

Troubleshooting image 4

EFFLORESCENCE

Troubleshooting image 7

FISH EYES

Troubleshooting image 8

DIRT OR DUST

IN COATING

Troubleshooting image 9

COLOUR DIFFERENTIAL

Troubleshooting image 10

DE-LAMINATION BETWEEN COATS

Rejection occurs from the application of a higher surface tension coating over a lower surface tension surface – the classic ‘water on wax paper’ effect.

Possible causes relate to those factors that might make for the surface below to be of a lower surface tension. These could include:

  • Surface below is too glazed or too smooth

  • Concrete curing agent present; especially wax type

  • Contamination on surface

  • Admixtures in concrete for greater water repellency, e.g. Stearic Acid

  • Densified surface reduces ‘wetting’ effect of applied coating

  • Incompatible coating types

Avoidance is based on ensuring the ‘wettability’ of the concrete surface. The water droplet or small puddle soak-in test is valuable as is applying a small test area of the intended coating onto the concrete surface.

Remediation options include:

  • Grinding off the rejected coating back to bare concrete

  • ‘Wetting’ or ‘activating’ the rejected surface with a surface tension increasing fluid such as Ecoshield's re-coating fluid and applying another coat. This will reduce the severity of the condition and maybe client acceptable but some effect will still be apparent. A test area is recommended for this option.

Cratering

CONDITION ONE

Rejection (Cratering)

Loss of Wet Edge / Overlap Marks

CONDITION TWO

Most overlap marks are caused by application of coating over an area of coating that has commenced to dry and has lost flowability. In this example the contractor ran out of coating product and left premises to obtain more – upon return and then applying the rest of the coating to the previously applied coating that had started to set up, the result being the rough orange peel overlap junction.

Possible causes include:

  • Too long a delay in the overlapping or joining up of coated areas.

  • High temperatures at application so rapid loss of wet edge property

  • Coating applied too thin so it dries quicker

  • The applied coating is starting to set up and thickening (increasing viscosity) with reduced flowability and leveling.

 

Avoidance:

  • One person mixes and pours and another person spreads if possible when coating larger areas.

  • Pour and spread as soon as possible after mixing of components

  • Apply in the cool of evening on hot days. Outgassing bubbles can occur if coated early on a hot day as slab heats (see later Osmotic blistering).

 

Remediation options include:

  • Abrading the ‘orange peel’ effect wet edge loss marking to make flat. Then applying a rectification coat over the entire floor

Overlap

CONDITION THREE

De-lamination / Peeling

Troubleshooting image 11

De-lamination is a separation of the applied coatings from the substrate or coated surface below it.

Possible causes include:

  • Clean surface on the underside of the separated coating:

  • Contaminated surface

  • No substrate surface wetting by the coating (surface too smooth, water repellant  admixture in concrete, curing agents on surface of concrete)

  • Incompatible coatings with one layer peeling off the other

 

Adhered material to underside of coating:

  • If self-leveling compound

    • Too much water in leveling compound mix can make it powdery or have less cohesive     (internal) strength

    • No, or inadequate abrasion or priming of the surface prior to leveling compound use

  • If mainly cement

    • Possible laitance from excess water on surface of concrete at pour or prior to cure.

    • Cement or sandy material spread on surface after slab pour

    • Heavy rain on slab soon after pour

 

Water in de-lamination blisters:

  • Osmotic blistering as per the above lower right hand photo. Water within slab diffuses to the surface and meets an impervious membrane coating (Epoxy, Polyurea or Polyaspartic). Hydrostatic pressure leads to blistering or localised de-lamination of the coating.

  • Salts visible at de-lamination

  • Efflorescence can force a coating from the concrete surface

 

Avoidance:

  • Check for wettability of surface to be coated prior to coating by using water beading test (see below).

  • Diamond grind to ensure surface contamination or smoothness removed.

  • Hit self leveling compound with a hammer to see if it fractures off the substrate or crumbles easily.

  • Firmly apply and drag a screwdriver over the substrate surface. If Powdery and easily disturbed, then possible laitance, poor concrete mix, excess sand in surface layers from overworking surface or too much water contacting surface prior to cure, might be an issue.

  • Too highly glazed by steel troweling to a shiny surface. Diamond grind to roughen surface to increase surface tension for better wetting of the coating and also to allow for more mechanical adhesion of the coating.

  • Use Eco Bond to enhance adhesion properties by functioning as a tie coat.

  • Efflorescence can be virtually avoided by use of penetrating and densifying coatings such as Eco Seal and Eco Densi Shield.

 

WATER BEADING TEST:
Apply beads of water to slab and wait for 1 minute.
Water should soak into slab and not be left on the surface in a bead.

 

Left hand side is a pass - Right hand side is fail

 

Remediation:

  • Grind back to bare, confirming water bead test and surface integrity via screw driver scrape and then resurfacing.

  • If surface soft and friable the use penetrating sealer Eco Seal, Densify with Eco Densi Shield.

  • If water bead test is still not promising after the diamond grind then apply Eco Bond as an adhesion promoting tie coat.

Delam /Peeling
Efflorescence

Efflorescence

CONDITION FOUR